SUNRPC: mark bulk read/write data in xdrbuf

Adds a flag word to the xdrbuf struct which indicates any bulk
disposition of the data. This enables RPC transport providers to
marshal it efficiently/appropriately, and may enable other
optimizations.

Signed-off-by: Tom Talpey <tmt@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

5 files changed, 11 insertions, 1 deletions

diff --git a/fs/nfs/nfs2xdr.c b/fs/nfs/nfs2xdr.c
index 1c570948fc16..668ab96c7b59 100644
--- a/fs/nfs/nfs2xdr.c
+++ b/fs/nfs/nfs2xdr.c
@@ -251,6 +251,7 @@ nfs_xdr_readargs(struct rpc_rqst *req, __be32 *p, struct nfs_readargs *args)
         replen = (RPC_REPHDRSIZE + auth->au_rslack + NFS_readres_sz) << 2;
         xdr_inline_pages(&req->rq_rcv_buf, replen,
                          args->pages, args->pgbase, count);
+        req->rq_rcv_buf.flags |= XDRBUF_READ;
         return 0;
 }
 
@@ -313,6 +314,7 @@ nfs_xdr_writeargs(struct rpc_rqst *req, __be32 *p, struct nfs_writeargs *args)
 
         /* Copy the page array */
         xdr_encode_pages(sndbuf, args->pages, args->pgbase, count);
+        sndbuf->flags |= XDRBUF_WRITE;
         return 0;
 }
 
diff --git a/fs/nfs/nfs3xdr.c b/fs/nfs/nfs3xdr.c
index 8a225fbe9ee2..616d3267b7e7 100644
--- a/fs/nfs/nfs3xdr.c
+++ b/fs/nfs/nfs3xdr.c
@@ -346,6 +346,7 @@ nfs3_xdr_readargs(struct rpc_rqst *req, __be32 *p, struct nfs_readargs *args)
         replen = (RPC_REPHDRSIZE + auth->au_rslack + NFS3_readres_sz) << 2;
         xdr_inline_pages(&req->rq_rcv_buf, replen,
                          args->pages, args->pgbase, count);
+        req->rq_rcv_buf.flags |= XDRBUF_READ;
         return 0;
 }
 
@@ -367,6 +368,7 @@ nfs3_xdr_writeargs(struct rpc_rqst *req, __be32 *p, struct nfs_writeargs *args)
 
         /* Copy the page array */
         xdr_encode_pages(sndbuf, args->pages, args->pgbase, count);
+        sndbuf->flags |= XDRBUF_WRITE;
         return 0;
 }
 
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 4dbbf44727ea..5f353d4686b6 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -1856,6 +1856,7 @@ static int nfs4_xdr_enc_read(struct rpc_rqst *req, __be32 *p, struct nfs_readarg
         replen = (RPC_REPHDRSIZE + auth->au_rslack + NFS4_dec_read_sz) << 2;
         xdr_inline_pages(&req->rq_rcv_buf, replen,
                          args->pages, args->pgbase, args->count);
+        req->rq_rcv_buf.flags |= XDRBUF_READ;
 out:
         return status;
 }
@@ -1932,6 +1933,7 @@ static int nfs4_xdr_enc_write(struct rpc_rqst *req, __be32 *p, struct nfs_writea
         status = encode_write(&xdr, args);
         if (status)
                 goto out;
+        req->rq_snd_buf.flags |= XDRBUF_WRITE;
         status = encode_getfattr(&xdr, args->bitmask);
 out:
         return status;
diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h
index c6b53d181bfa..0751c9464d0f 100644
--- a/include/linux/sunrpc/xdr.h
+++ b/include/linux/sunrpc/xdr.h
@@ -70,7 +70,10 @@ struct xdr_buf {
 
         struct page **  pages;          /* Array of contiguous pages */
         unsigned int    page_base,      /* Start of page data */
-                        page_len;       /* Length of page data */
+                        page_len,       /* Length of page data */
+                        flags;          /* Flags for data disposition */
+#define XDRBUF_READ             0x01            /* target of file read */
+#define XDRBUF_WRITE            0x02            /* source of file write */
 
         unsigned int    buflen,         /* Total length of storage buffer */
                         len;            /* Length of XDR encoded message */
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index b19bacf42564..19c129ed6467 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -874,6 +874,7 @@ rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
         buf->head[0].iov_len = len;
         buf->tail[0].iov_len = 0;
         buf->page_len = 0;
+        buf->flags = 0;
         buf->len = 0;
         buf->buflen = len;
 }